letter box springs...source

[ss]

The springs in my letter box flap are all broken. I have checked ebay and googled but no joy as all are too large. There appear to be 2 springs per flap, that is me assuming they havent just halved in two. The pieces I have are about 10 mm long and an outside diameter of 3mm. They dont fit on a rail but inside a groove so the external diameter is more important than the inside diameter. I assume where broken off there would be 2 straight lugs. To me the springs appear quite small but cant see how I could incorporate anything larger (diameter)

Any suggestions for a source or indeed a DIY solution.

[Bob Minchin]

If you have one of those older style hardware shops, they normally have a selection box of springs from which they might just be able to find something suitable.

Otherwise a search for torsion springs might throw up something?

[Brian Gaff]

New letterbox? Brian

[ss]

Last resort :-) blue tack comes before that.

[Kevin]

Clothes peg springs too big?

A length of piano wire (e.g. from a model shop) wrapped round a former, ends left as needed? Stiffness is proportional to the fourth power of wire diameter, so make it close to the original.

[ss]

Yip clothes pegs too big so may need to look at piano wire. With me taking a couple of pins out to access the broken springs and then tapping them back in I have stiffened the movement of the flap so at least in the short term it shouldnt flap in the wind.

[chrisj.doran%proemail.co.uk]

When mine broke, I used a length of curtain wire which is a coiled spring i n a plastic sheath about the diameter you need. That was 20 years ago and t he wire considerably older; do they still make it? I cut it to the full len gth of the flap and put small screws in each end. Whilst I guess I should h ave uncoiled and straightened a bit to provide pressure, the weight of the flap seems sufficient for its position in a short open-ended porch.

Chris

[Bob Minchin]

If you are starting think about making a spring then good sources of spring wire can be pump action soap dispensers and some of their close relations, the pump action toothpaste dispenser.**

These use coil springs of about the right gauge wire that could be fashioned into torsion springs round a suitable sized mandrel. many are stainless steel so won't rust in your application.

hth

** not all use metal springs, some return action is provided by the plastic moulding

[ss]

Previous suggestion re curtain wire...that would be too thick.

I think I will need to fashion something myself so some good ideas given re sources for wire, I should find something lurking around the house.

[Johny B Good]

Model shops probably don't stock stainless steel piano wire, afaicr, theyre just steel. Aside from the lack of resistance to rusting, piano wire is an effective way to homebrew suitable springs.

However, you might consider a suitably guaged length of NiTinol wire (of memory wire fame) since this has about 6 times the elasticity of the best stainless steel spring wire. The memory effect isn't the only remarkable feature of this alloy.

You'd only need to use about a fifth the length of a stainless steel wire spring to get the same elastic range. The only complication being the need to heat the coil on its forming mandrel to 500 deg C or so to set the coil shape.

[Michael Chare]

How about a lead weight glued to the inside bottom edge?

[ss]

Yes I thought about that if nothing else can be done, I`ll get a narrow strip of something heavy and fix it on.

[PixelMover]

replying to ss, PixelMover wrote:

[Bob Eager]

One would hope that they've found the springs by now, in the intervening four and a half years.